Water purification cartridge for a dental instrument



FIG. 1 is a perspective view of a water purification cartridge for a dental instrument showing our new design;

FIG. 2 is a side elevational view thereof, the opposite side, top, and bottom views are identical;

FIG. 3 is an end elevational view thereof, the opposite end being a mirror image; and,

FIG. 4 is a sectional view taken along the line 4--4 of FIG. 2. 

The ornamental design for a water purification cartridge for a dental instrument, as shown and described. 